Rabble shaft and arm for furnaces.



No. 872,827. PATENTED DEG. 3, 1907, A. V, LEGGO..

RABBLE SHAFT AND ARM FOR PURNAGES. APPLIoATIoN HLM APR.6.1906.

2 SHEETS-SHEET 1.

No. 872,827. PATENTED DEC. 3, 1907. A. V. LEGGO.

RABBLE SHAFT AND ARM FOR FURNAGBS.

APPLIUATION FILED APR.61906.

2 SHEETS-SHEET 2.

UNTTED sTaTEs EATEET eEEreEQ ARTHUR VICTOR LEGGO, OF BALLARAT, VICTORIA,AUSTRALIA.

RABBLE SHAFT AND ARM FORZURNACES.

Specification of Letters Patent.

, Patented Dec. 3, 1907.

Application filed April 6| 1906. Serial No. 310.324.

furnaces for roasting, de sulfurizingchlorid-l izing, dehydrating, ordrying ores and other substances, of which the following is aspeciification.v

This invention relates to improvements in and connected withrabble'shafts and arms for furnaces for roasting, desulfurizing,chloridizing, dehydrating, or drying ores, and other substances, vandhas been devised principally in order to provide means for more simplyand eifectually circulating a cooling agent, such as water, throughoutthe said rabble shaft and arms, than any at present in use.

In carrying out my invention I prefer to make the rabble shaft insections and bolt them together, buty when more convenient they may becast in one piece. The said shafts are hollow and provided with acentralvertical down pipe, to the top of which is connected a supply pipe fordeliveringr the cooling agent thereto. I provide the down pipe Witlr ajet for each rabble arm attached to the shaft. Said jet does not enterthe rabble` arms but is so positioned that it di' rects a stream ofwater along the center of the hollow rabble arm. The water in the downpipe is maintained at any suitable pressure, and the velocity with whichthe water enters the rabble arm from this jet causes a central currentof cool water to iiow from the inner to the outerend of the arm,which inturn ishcated and displaced by the cool water continuously injected, theheated water from all the arms returning to the rabble shaft andescaping through an overflow pipe situated in the top thereof. .A con-4tinuous circulation of water is thus effected through cach arm 'to keepit cool. The.

down pipe with the jets can be withdrawn from the rabble shaftthroughthe top thereof for the purpose of renewal or repairs with-.

out interfering in any way with theI rabble shaft or arms in thefurnace. t" My invention also consists in the combination with a rabblearm constructed as described of two rows of ,.iuovable teeth one oneither side thereof thc front *row being narrower than thoseconstituting, the back row. Both rows of teeth are set at equaldistancesapart, the front or narrow teeth being formed with broad feet which feetapproximate in width to the spaces between the'back teeth. The.,- teethare so placed on the rabble arm 'as that when the rabble arm is inmotion the paths of the front teeth are immediately between the paths ofthe'baek teeth.

In cases where the rabble armsiitted with removable teeth as previouslydescribed are used in furnaces in which the inclination of the'hearthsis not sufficient to cause the ore to pass`through the furnace withsufficient rapidity, I may remove some of the end teeth and substitutetherefor one or more .Y

teeth so constructed as that they oil'er oblique surfaces to. the orewhereby it is forced 'more rapidly from the path of one arm to To retardthe passage of that of the next. the ore the oblique teeth are reversed.

In order to enable the teeth to be attached to and removed from therabble arm I provide rectangular projections both on the top and bottomof the rabble arm. Recesses are formed in the -jaws ofboth the frontandback teeth to enable them, to pass over and engage with theprojections aforesaid. The teeth are kept in their properposition bymeans of spacing bars which are attached to the-arm by means of pinspassing through said spacing bars and arm. order to enable oblique teethto be substituted for some of the end teeth these oblique teeth areprovided with 'two jaws having suitable reoesses to enable them toengagewith and 'y pass over and'along the said arm.

In some cases-it may be desirable to use a double, instead of a singlerabble arm, in which case I dispense with the projections on the arm,and substitute for the teeth constructed as before described, obli ueteeth set at a different angle on one si e of the rabble shaft to thoseAon the other. By this means the ore left stagnant by the teethon one armisstirred bythose on the other.

Referring now to the 'drawingsrelfigure l is a sectional elevation of a'rabble shaft and arm constructed according tol'my invention. Fig. 2 is aplan of Figi. Fig. 3 is a cross section of the rabble arm shown in Fig.1.

Fig: vt is a cross section of the rabble shaft on'the obliquely dottedlinec,- a, Fig. 1.

Fig. 4 vis a further section on the line of F ig. 1. Fig. 5 isape-rspective view of that portion. ofthe rabble shaft te which the yrabble arm is attached. Fig. 6 is a perspective view of portion of arabble arin inverted, with teeth attached. Fig. 7 is a perspective viewof a back tooth. Fig. 8 is a perspective viewof a fronttooth. Fig. 9 isa perspective view of a s acing bar. Fig. l() is an inverted plan of adouble rabble arin having oblique teeth.. Fig. 11 isa perspective viewof an obli( ue' tooth for attachment to the double rabble arin shown inFig. V10.

1 represents the rabble shaft. 2 is the rabble arin attached thereto. 3is the central verticaldown pipe in said rabble shaft, the top of whichdown pipe is attached to the stu'llingjbox 4 which is bolted to the topof the rabble shaft. 5 is a' supply pipe which enters'the stulling box 4and delivers the cooling agent'to the down pipe 3. 6 is the jet in thesaid down pipe 3 situated iin rnediately opposite the center of theopening in the rabble arm 2. Said jet 6 may be screwed into or otherwiseallixed. to the down pipe 3.

8 are projections on the inside of the rabble shaft, and near thelbottoni of the down pipe 3. lBetween the said projections 8 areopenings?) through which the water in the rabble shaft 1 passes tothelsurnp 1() in the bottom thereof; 11 is a tap to withdraw the waterfrom said sump 1() when it is desired to cleanse theshaft 1 of any solidmat- .ter deposited in it without withdrawing the rabble shaft from thefurnace.

12 is an overflow pipe near the top of and through which the heatedwater escapes l from the rabble shaft 1.

13y is a trough having a pipe 14 attached tothe bottom thereof for thepurpose of conveying the water therefrom.

On one end of the rabble arin 2 is a neck 15,which enters a hole 16 in.the rabble shaft 1. The shaft 1 is thickened round the hole 16 (see Fig.5) both to give strength to the shaft at this point and to provide agreater bearing surface for the neck 15 en the end of the rabble arm 2.Between the neck 15 and the flange 17 on the arm 2 is a collar 18, whichis of smaller diameter than the inside of the annular ring 1l) castintegrally with and on the side of the rabble shaft 1. rl`he spacebetween the outside of the collar 18 and the inside of the annular ring1S), when the arm is in position, forms an annular re-. cess 20, whichdirects any leakage of water, at the junction of thc rabble shaft 1 andthe rabble arm 2, to the passage 21. leading to one or other ol' thepassages 22 and 23,'which pass down opposite sides of' the rabble shaft1 to l,the bottom of the said shaft, where they meet. 'lho rabble arm 2is securely fastened to thel rabble. shaft l by means of bolts passingthrough-tho flanges 17 ofthe arm 2 and the coupling piero 24 situated onthe opposite sido of tho said shalt l.

'llhe raljililc arms may if preferred, be

aras-e7 keyed to the rabble shaft, and the means shown inv the drawingspermit, by the use of suitable. tools, of their being renewed orreplaced from the outside of the furnace, there-4 by: obviating thei'ieccssity for cooling down the furnace to effect repairs. When thereis much leakage of water from the junction of said rabble shaft 1 andsaid rabble aiin 2, the small .space between the edge of the annularring 19 and the llange .17 when the arni is iii position can be calkedwithyasbestos liber, or other suitable material. l'he two passages 22and 215 are only required, when these rabble shafts are made insections.

\.'hen` the rabble shaft is cast in one piece,l only one of thesepassages 22 or ,22%, will be required, and the passages 21 all made tolead toit. 25 is a tap to withdraw the rontents from the said passages22 and 23.

2t? are rectangular projections on the top, and rectangular projectionson the bo-ttoin, of the rabble arm 2over which the recesses 28 formed inthe jaws 2*.) of the front and back teeth 3l) and 3&1 respectively arepassed. 32 are spacing bars to keep the teeth forming any row at givendistances apart. B3 are pins which pass through and hold the saidspacing bars 32 to the rabble arni. The back teeth 31 are broader`thanthe front teeth 30, and their effect on passing through the ore is toform deep furrow s in'it, thereby exposingas great a surface of ore aspossible in a given hearth area. 'lhc front teeth 30 are narrower, andhave at their bottom end a broad foot 254. These front teethBlliininediately preceding they do the back teeth 551, effectively openup the ridges of ore forming the furrows inade by the back teeth on theprevious revolution ofk the rabble, and a very thorough and frequentexposure of the ore particles to the oxidizing atmosphere is therebyattained.

yTo connect the said teeth '250 and 31 to the rabble arin 2, the jaws2E) are passed over the arin between the rectangular projections 26 and27, and then slid along the arm until the recess 28 formed. iii the jaws3f) covers the said projections, when the teeth 7will be iirnilysecured. When the inclination of the .hearths is foundzto be insullcientto cause the ore to pass through" the furnace with sullicient rapidity,i remove some of the end teeth il() and 3l of the rabble arm, andsubstitute one or more teeth 35, which are so constructed as that theyoffer oblique surfaces to the "oro, and force it more rapidly from thepath ol' ong; arm to that of the next. When it is desired to retard thepassage of the ore through the furnace, the teeth 35 are reversed, whenthe required result will bc el l'ectei l 536 (see Fig. 1(1) illustratesa double-rabble arm, fitted with obliquo teeth 37, those on one aruistirring the ore left stagnant by those on the other, and the teeth onone arm' being placed at the opposite angle to those lon the other arm,so that when in motion the outwardly-throwing effect of those 0n the onearm will be counteracted by the in- \\'ardlythrowing e'ect of those onthe other. It is quite obvious ,that rabble shafts with more than tworabble arms attached above each hearth may be used, and the paths of therabble arms of one shaft can overlap those ot the rabble shaft or shaftsnext adjacent without coining'into contact, so long as the rabble shaftsare made to rotate'a-lternately in right and left hand directions.

The rabble shaft 1 is driven by worm or bevel gearing situated above 0rbelow the furnace or in anyqther approved manner.

What I do laila as my invention, and dev sire to secure hy LettersPatent, is

1. 'In an apparatus of the class described, a rabble arin havingprojections on the top and bottoni thereof, anda plurality of removableteeth having recesses forming jaws for engagement with the project-ions.

' 2. In an apparatus of' the class described, a rabble arm havingprojections at the top v and bottom thereof, a plurality of teeth, one

pr more ot' the same having feet, and jaws associated with said teeth atthe opposite ends for detachable engagement with the projections on therabble arm.

In an apparatus of the class described, a rabble arm having projectionsat the top' and bottom thereof, a plurality of teeth, one or more oi thesame having'i'eet, jaws associated with said teeth at the opposite endsfor detachable engagement with the projec-` tions on the rabble arm, andspacer bars interposed between thel teeth and projections for holdingthe teeth suitably spaced from each other.

4. In an apparatus of the class described, a double rabble arm havingprojections at its opposite side edges, oblique teeth'carried by therespective arms,'one` series of the teeth carried by one arin arrangedat an angle opposite to the series of teeth carried by the other arm,jaws formed integral with each of the teeth for detachable engagementwith the projections, and means associated with the teeth for spacingthe saine from each other.

5. In an apparatus of the class described,

In testimony whereof I have hereunto set my hand in presence of twosubscribing witnesses.

I ARTHUR VICTOR LEGGO.

Witnesses 5 WALTER S. BAYs'roN, FRANK BAYsToN.

